1,905 research outputs found
Development of Urban Electric Bus Drivetrain
The development of the drivetrain for a new series of urban electric buses is presented in the paper. The traction and design properties of several drive variants are compared. The efficiency of the drive was tested using simulation calculations of the vehicle rides based on data from real bus lines in Prague. The results of the design work and simulation calculations are presented in the paper
Report of review of St Stephen’s Children’s Centre, Newham: services for children aged up to 3 years
Formation of surface depressions is a significant geological hazard. Prediction of future sinkholes in
buried karstic areas needs knowledge about the subsurface. In order to determine the varying topography
of the karstifiable bedrock we carried out multielectrode measurements. Due to the hard field conditions,
the bedrock depth could not be detected. The resistivity anomalies in some places had a seasonal variation
(low-resistivity in springtime, high-resistivity in the end of summer); therefore we interpreted the
springtime resistivity lows as indicators of locations with high water content, that is as high porosity,
saturated with water. At the same time, when pushing the current- and potential electrodes into the ground,
we discovered a regularity in the areal distribution of the soil's rock debris content. Therefore we carried
out a systematic electrode-pricking experiment, and categorized the soil's "toughness" corresponding to
soft penetration, scratching or blockage within the upper 30 cm. We have found a close relationship
between the locations of resistivity- and the soil's toughness extremes. From some epikarstic features we
think that high "pricking probe" values indicate smaller depths of the bedrock. The corresponding
(springtime) resistivity minima may indirectly indicate more or less collapsed horsts of the carbonate rock
Model independent analysis of nearly L\'evy correlations
A model-independent method for the analysis of the two-particle short-range
correlations is presented, that can be utilized to describe e.g. Bose-Einstein
(HBT), dynamical (ridge) or other correlation functions, that have a nearly
L\'evy or streched exponential shape. For the special case of L\'evy exponent
alpha = 1, the earlier Laguerre expansions are recovered, for the alpha = 2
special case, a new expansion method is obtained for nearly Gaussian
correlation functions. Multi-dimensional L\'evy expansions are also introduced
and their potential application to analyze rigde correlation data is discussed
Electron supersurface scattering on polycrystalline Au
Supersurface electron scattering, i.e., electron energy losses and associated deflections in vacuum above the surface of a medium, is shown to contribute significantly to electron spectra. We have obtained experimental verification (in absolute units) of theoretical predictions that the angular distribution of the supersurface backscattering probability exhibits strong oscillations which are anticorrelated with the generalized Ramsauer-Townsend minima in the backscattering probability. We have investigated 500-eV electron backscattering from an Au surface for an incidence angle of 70° and scattering angles between 37° and 165°. After removing the contribution of supersurface scattering from the experimental data, the resulting angular and energy distribution agrees with the Landau-Goudsmit-Saunderson (LGS) theory, which was proposed about 60 years ago, while the raw data are anticorrelated with LGS theory. This result implies that supersurface scattering is an essential phenomenon for quantitative understanding of electron spectra
IoT applications utilizing excess heat in electrical lighting fixtures
The development of IoT instrumentation will always be strongly influenced by the properties of the power supply system. A large number of IoT nodes creates a danger of extra expenditures when changing the battery. For this reason, the development of supply nodes tends to prefer systems capable of battery-less operation, obtaining energy from other sources. This article deals with an alternative method of electrical energy acquisition form the excessive heat appearing in LED lighting fixtures utilizing large-area LED chips. A Peltier cell was used for the conversion of heat energy to electrical energy, connected as thermo-electric generator into the thermal chain
A diákfirkák üzenete - mit és miért firkálnak a serdülők?
Kutatásunkban közĂ©piskolás diákok firkálási szokásait mĂ©rtĂĽk fel saját szerkesztĂ©sű kĂ©rdĹ‘ĂvĂĽnk segĂtsĂ©gĂ©vel. FĹ‘bb kutatási kĂ©rdĂ©seink a következĹ‘k voltak: Milyen gyakran firkálnak a serdĂĽlĹ‘k? Milyen formákat, alakzatokat, szövegeket firkálnak a leggyakrabban? Milyen Ă©rzelmi állapotban firkálnak a diákok? Mi motiválja Ĺ‘ket firkák kĂ©szĂtĂ©sĂ©re? Vizsgálati szemĂ©lyeinket 4 szabadkai közĂ©piskola diákjai közĂĽl választottuk ki. A kĂ©rdĹ‘Ăv mellett megkĂ©rtĂĽk Ĺ‘ket arra, hogy a leggyakrabban firkált motĂvumaikat rajzolják le. EredmĂ©nyeink szerint a diákok 58%-a naponta firkál. Nincs lĂ©nyeges kĂĽlönbsĂ©g az elsĹ‘s Ă©s a negyedikes, illetve harmadikos diákok firkálási gyakoriságában, vagyis a firkálási kedv kutatási eredmĂ©nyeink szerint nem csökken az Ă©letkor elĹ‘rehaladtával. A vizsgálati szemĂ©lyek többnyire az iskolai Ăłrák alatt vagy a szĂĽnetekben firkálnak, leggyakrabban akkor, amikor unatkoznak vagy szerelmesek. A serdĂĽlĹ‘k kĂ©rdĹ‘ĂvĂĽnk eredmĂ©nyei alapján leggyakrabban szemĂ©lyek, egyĂĽttesek, sportolĂłk neveit, szöveget, valamint a saját aláĂrásukat Ă©s absztrakt alakzatokat firkálnak. A közĂ©piskolák összehasonlĂtĂł vizsgálata során kiderĂĽlt, hogy a kĂĽlönbözĹ‘ közĂ©piskolákban más-más motĂvumok jelennek meg, illetve más-más motĂvumok dominálnak. In our research we mapped out the habit of student's scribbling with our self — made questionairre. The main questions of study were the following: How often do adolescents make scribbles? What shapes, formations, texts do they scribble most frequently? In what emotional state do students make scribbles? What motivates them in the making? The subjects of our study were from four highschools in Subotica. Besides doing the questionnaire, we asked them to make a drawing of their most often occuring scribblemotives. Based on the results it can be said that 58% of our study subjects make scribbles every day. There are no differences between first and fourth, as well as third class students in the frequence of their scribbling, namely the pleasure of scribbling doesn't decrease with age. Students make scribbles during lessons or recess, generally when they are bored or in love. Based on our results it can be said that adolescents scrawl names of persons, ensembles and sportsmen, texts, their signature and abstract motives. During the comparative analysis of the different secondary schools it turned out that different motives occur and are dominant in different highschools
Photoluminescence rings in Corbino disk at quantizing magnetic fields
Spatially resolved photoluminescence of modulation doped AlGaAs/GaAs
heterojunction was investigated in a sample of Corbino disk geometry subject to
strong perpendicular magnetic fields. Significant spatial modulation of the
photoluminescence was observed in form of one or more concentric rings which
travelled across the sample when the magnetic field strength was varied. A
topology of the observed structure excludes the possibility of being a trace of
an external current. The effect is attributed to formation of compressible and
incompressible stripes in a 2DEG density gradient across the sample.Comment: 5 two-column pages, 4 figures (one of them in color
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